ExJdbited at Windsor. 
519 
far as the crossing, and are then riveted to a taper plate a foot 
wide at the broader end and 8 inches at the other by -f^-inch 
thick, which is channelled to hang over the rail that is being 
crossed. The junction between the two ends of the sliding rails 
is made by a piece of square iron 1 inch in the side, about 
